Transformer



Dec. 14 1926. 1,610,784

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.jjjjj!) Inventor: Tatsu chiro lsono, y 4. M

H is Attorney 'm'rsurcnmo ISONO, or

TOKYO, JAPAN, ASSIGNOR TO GENERAL ELECTRIC COMPANY,-

'A CORPORATION OF NEW YORK.

TRANSFORMER.

Applicaation filed April 10, 1919, Serial No. 289,027, and. in JapanApril 12, 1918.

My presentinvention relates to a device for changing or transformingelectric voltages, and more particularly to a vacuum tube device foraccomplishing the desired purpose.

The object of my invention is to produce a simple and efficient devicefor transforming voltages, and particularly to secure a secondaryvoltage of lower value than the primary voltage appliedto the device.

The novel features which I believe to be characteristic of my inventionare pointed out with particularity in the appended claims. The inventionitself, however, both as to its organization and method of operation,together with further objects and advantages thereof will best beunderstood by reference to the following description taken in connectionwith the accompanying drawing in which Fig. 1 is a diagrammaticrepresentation of a device constructed in accordance with my invention;Fig. 2 shows the wave form of the primary voltage and secondary currentset up in the device; Fig. 3 is a diagrammatic representation of amodification, in which two similar devices are used in parallel toobtain a transformation of voltage waves of opposite polarity; Fig. 4shows the wave form of theprimary and secondarycurrents in thearrangement shown in Fig. 3; and Fig. 5 shows a further modification ofmy invention.

It has been common practice in the past to use transformers inconnection with alternating current voltage measuring instruments, wattmeters, frequency meters,'etc.,

for changing the primary voltage mto a lower voltage having the samewave form. In cases where transformers are used with very high voltagesthey have become very bulky and their construction in practice has beenlimited by reason of insulation difiiculties. A more specific object ofthe resent invention is to overcome these disa vane tages. It is wellknown that if two electrodes are inserted within a vacuum tube such asthat indicated as 1 in Fig. 1 and one of the electrodes 2 is made in theform of a lamp filament and is heated by means of a battery 3, while theother islands as a conducting plate 4, electric current will flowbetween the two electrodes only in one direction. 1

In the case of the present invention this characteristic of such adevice is utilized.

vice versa. polarity 10 and 11, are provided in this case in addition tothe electrodes 25nd 4, I provide two other electrodes 5 and 6. These twoelectrodes are connected to opposite terminals of the source of highvoltage which it is desired to measure. In the present case the sourceis indicated as the secondary of transformer 7. It will be noted thatthe.

electrodes 2 and 4 are locatedbetween the electrodes 5 and 6. A battery9 is also connected in circuit between the cathode 2 and the cooperatinganode 4, the positive terminal of the battery being connected tot theanode 4 and the negative terminal to the cathode 2. The current flowingbetween the cathode 2 and anode 4 depends upon the voltage betweenelectrodes 5 and 6 as well as upon the voltage'of the battery 9. Henceif the voltage between the electrodes 5 and 6 is an alternating voltagethe current between electrodes 2 and 4 increases when the electrode 5becomes negative and the electrode 6 becomes positive and decreases whenthe electrode 5 becomes positive and the electrode 6 becomes negative byreason of the electrostatic fields produced in the neighborhood of theelectrodes 5 and 6. In other Words, current flowing from the battery 9is proportional to the voltage between the electrodes 5 and 6. Thecurrent which flows between electrodes 2 and 4 will have a component ofthe form indicated at I in Fig. 2, which corresponds to the half waveform of the voltage wave V when the electrode 6 is positive. The efi'ectwill be the same as if a voltage, much smaller than but directlyproportional to that between electrodes 5 and 6, were applied betweencathode 2 and anode 4. The electrodes 5 and '6 are not necessarilylocated within thevacuum tube but may be outside of the tube asindicated in Fig. 5, and if desired, may be electrically connected toone of the electrodes, 2 or 4 as indicated by'dotted lines 12 or 13.

In order to obtain a current in which both half waves of the primaryvoltage can be reproduced two devices similar to that shown in Fig. 1may be connected in parallel in the manner indicated in Fig. 3. In thiscase thesource of voltage V is connected to the two devices in such away that when the electrode nearest the filament of one device ispositive, the electrode' nearest the filament of the other device isnegative and Separate batteries of the proper for the two devices andthe current flowing through the twodevices may be measured by means of ameter M which is connected in series with both of the devices. The waveform of the alternating current flowing through this meter M isindicated in Fig. 4 by the curve I,. This current corresponds in waveform to the voltage wave V and is directly proportional to the voltage.This current corresponds to the current which is obtained from thesecondary of the ordinary transformer which is used in similar cases.

What I claim as new'and desire to secure by Letters Patent of the UnitedStates, is

1. A voltage transforming device comprising an evacuated receptaclecontaining two electrodes towhich the voltage to be transformed may beapplied, a cathode adapted to emit electrons and a cooperating anodelocated between said two electrodes, a source of direct currentconnected to said cathode and anode, and a measuring instrumentconnect-ed in series with said source of direct current; V

2. A voltage transforming device comprising two evacuated receptacles,each of which contains two electrodes to which the voltage to betransformed may be applied, and a cathode adapted to emit electrons anda cooperating anode located between said two electrodes, sources ofdirect current connected between cathode and anode of each receptacle, ameasuring instrument in series with both of said sources of current, andcircuit connections for applying the Voltage to be transformed to saidfirst named electrodes in such a way that when the electrode nearest thecathode of one receptacle is positive the electrode nearest the cathodeof the other receptacle is negative.

In witness whereof, I have hereunto set "my hand this seventeenth day ofMarch,

'TATSUICHIRO ISONO.

